The Status of MINOS Mike Kordosky University College London for the collaboration

Outline ● NuMI / MINOS introduction and physics goals ● MINOS Detector description ● Cosmic Rays and atmospheric at the Far Detector ● Experience with beam running in the Near Detector ● Near term goals and Conclusion

What is MINOS? ● Main Injector Neutrino Oscillation Search ● Long (735 km) Baseline ● Intense Neutrino Beam (NuMI) ● Near Fermilab ● Far Soudan, MN Neutrino beam Near detector Far detector ● Muon neutrino disappearance ● Electron neutrino appearance ● Sterile neutrino component ● Atmospheric neutrinos MINOS will study: MINOS is the :

MINOS Collaboration The collaboration on the Fermilab site with Near Detector surface building in background Argonne – Athens – Benedictine – Brookhaven – Caltech – Cambridge – Campinas – Fermilab – College de France – Harvard – IIT – Indiana – ITEP Moscow – Lebedev – Livermore – Minnesota, Twin Cities – Minnesota, Duluth – Oxford – Pittsburgh – Protvino – Rutherford Appleton – Sao Paulo – South Carolina – Stanford – Sussex – Texas A&M – Texas-Austin – Tufts – Univ. College London – Western Washington – William & Mary - Wisconsin 175 physicists 32 institutions 6 nations

 Disappearance Survival Probability ● “atmospheric” oscillations from a beam source ● strong test of alternative hypotheses ● Large improvement in  m 2 measurement ● primary limitation: protons on target nominal 3yr run

Electron Neutrino Appearance ● Much interest in e appearance and value of  13 ● Measurement very challenging with MINOS detector & NuMI beam! ● But, if  13 is close to CHOOZ limit, we will see a ~3  signal in about 3yrs of running ● Otherwise, will improve current limit by factor of 2-3

NuMI Beam 120 GeV/c p on graphite target Magnetic Horns focus  K  677 m decay pipe p,  K stopped Near detector Control neutrino spectrum -- Move horns -- Move target Neutrinos at the Main Injector

Near Detector ● Steel + Scint. ● 1km from Target ● 0.98 kton ● 282 steel planes ● B=1.2 T ● 64-anode PMTs ● High Rates ● QIE electronics – no deadtime! Near detector during construction Coil Hole Sci. Plane PMTs, QIE electronics Purpose Measure beam before oscillations Predict Far detector spectrum To Far detector Beam

Far Detector ● Soudan, MN ● 735 km from source ● 5.4 kton ● 486 steel planes ● B=1.3 T ● 16-anode PMTs ● 8x multiplexed ● VA electronics Far detector: completed July 2003 Field Coil Purpose Measure  -CC, NC  energy spectra, rates Search for e appearance PMTs & Electronics To Fermilab Veto shield Optical Readout 8m wide

CalDet in T7 1 m Optical Cables PMTs Beam ● CERN PS – T11: GeV/c – T7: GeV/c – mixed p,e,pi,mu beams ● Sixty 1-m 2 planes ● Light level ~ Near and Far ● No B-field ● Ran w/ Far & Near readout ● External PID: CER & TOF The CalDet Purpose: - Measure Response & Resolution - Characterize Event Topology - Confront & optimze MC - Develop Calibration Procedure - Study Near vs. Far readout

Detector Technology Special Thanks M. Proga 2.54cm Steel absorber (2.50cm in CalDet) Scint. 1cm thick, 4.1 cm wide WLS Fibers Multi-anode PMT Fiber ''cookie'' Scint. Plane Readout Cable PMT Dark Box ● Tracking-sampling calorimeter ● Segmentation: – 5.94cm longitudinal – 4.1cm transverse ● Planes rotated +/- 90 deg ● WLS collects/routes light to PMTs

Atmospheric Neutrinos 48  events Cosmic Rays Ex: Upward going muons ● First underground detector with B-field ● Can distinguish  vs.  -bar oscillations ● First publication (FC and PC analysis) to be submitted this summer

Moon Shadow ● Have collected 1e7 cosmic- ray muons in the Far Detector ● Can be used to observe the moon's shadow ● Used to determine angular resolution: < 1degree HE primary cosmic rays Far Detector

Near Detector: Single Spills LE beam ~3-4 events/1e13 ppp spill HE beam ~8 events/1e13 ppp spill spectrometer multiplexed Two views: “U vs. Z” and “V vs. Z”

Near Detector: Isolating Single Events ● continuous read-out for 18  s ● 18.9 ns timing resolution ● Single events isolated via timing and position: “Slicing” hit-time in spill (  s) 5 “batches”

Near Detector: Contained CC Event hit-time in spill (  s) ~1.5 GeV/c , ~1.1 GeV shower

Near Detector: Rock Muon hit-time in spill (  s) ~6.3 GeV/c 

Near Detector: Event Vertices ● Neutrino event vertex for data collected in May ● Already enough events to observe detector structure fiducial volume Partially instrumented plane (m) horizontal position (m) vertical position (m) Fully instrumented plane (m)

Near Detector: Muon Track Direction ● Figures show zenith and azimuthal angles of  -CC muon tracks ● Beam pointing towards Far Detector: – Zenith: Downward ~3.3 degrees, cos(  )=0.06 – Azimuth: Slightly west of true north:  =156 degrees ● Good agreement with expectations!

Near Detector: Energy Spectra ● Data collected for 3 target positions ● More than 1.3e5  -CC events recorded in May! Near Detector  -CC events reconstructed neutrino energy (GeV)

Far Detector: First Event ● First Event observed in the Far Detector: March 20, ● Event consists of a muon emanating from the rock in front of the detector. ● Muon points back to Fermilab and was in time with a beam spill.

Next Step: Choice of Beam Energy ● Run with low energy beam for first few months (~1e20 POT) ● Conduct initial oscillation analysis to check beam energy

Summary ● MINOS is taking beam data! ● Both detectors and NuMI beam operating rather smoothly. ● More than 140k nm-CC events recorded in Near Detector during May! ● Beam neutrinos observed in Far Detector! ● Initial oscillation analysis after ~1e20 POT, used to check beam configuration. ● Forthcoming atmospheric neutrino analysis.